Number of U.S. cases rising; most cases have been mild
MONDAY, April 27 (HealthDay News) -- Two recent cases of swine influenza A (H1N1) virus infection in Southern California raised the possibility that the virus can be transmitted by human-to-human contact, according to a report published in the April 24 issue of the U.S. Centers for Disease Control and Prevention's Morbidity and Mortality Weekly Report. Subsequently, the number of U.S. cases continues to rise and U.S. officials have declared it a public health emergency.
CDC researchers studied two children -- a 10-year-old boy and a 9-year-old girl -- who lived in adjacent California counties and who developed a febrile respiratory illness caused by the swine influenza A (H1N1) virus. The researchers found that neither of the children had direct exposure to pigs. They could not establish an epidemiological link between the two cases or identify any additional cases. In both patients, the viruses showed antiviral resistance to amantadine and rimantadine. It has since been determined that the virus is susceptible to the antivirals oseltamivir (Tamiflu) and zanamivir (Relenza).
The number of affected people in the United States has since risen to 20 patients as of Sunday, April 26: eight in New York, seven in California, two in Texas, two in Kansas and one in Ohio. Some of the cases were in people who had recently traveled to Mexico and all cases have been mild with all persons now recovered, explained Richard Besser, M.D., acting director of the U.S. Centers for Disease Control and Prevention, at a news conference on Sunday.
"Given the reports out of Mexico, I would expect that over time we are going to see more severe disease in this country," said Besser. "We have ramped up our surveillance around the country to try and understand better what is the scope, what is the magnitude of this outbreak."